What hardware for a proof of stake Ethereum validator ?
That’s it, the merge is going to happen sooner than later. You have collected 32 precious ether and you are just waiting for one thing, to be able to stake them and become a validator on Ethereum! But now, a question arises: what piece of hardware do I need ? The more curious will have already started to study the documentation made available on the installation processes of clients under development such as Prysm, Lighthouse or Teku. But concerning the hardware to acquire, the information is limited ! So I explored the question by going around the web, various Discords and doing tests. Here is an overview of the different possibilities available to us.
What are the selection criteria ?
Currently, specs are unfortunately only partially defined. Clients under development only integrate the beacon chain and merge specs. The first tests carried out are therefore not necessarily representative of what the protocol will be in the long term, once the full road map is in production.
In the meantime, Prysmatic Labs announces in the documentation of its client Prysm the following technical specifications:
Minimum specifications
Operating System: 64-bit Linux, Mac OS X 10.14+, Windows 64-bit
Processor: Intel Core i5–760 or AMD FX-8100 or better
Memory: 4GB RAM
Storage: 20GB available space SSDRecommended specifications
Processor: Intel Core i7–4770 or AMD FX-8310 or better
Memory: 8GB RAM
Storage: 100GB available space SSD
A typical computer will therefore be able to run the beacon chain as well as one, or several validators. However, this choice will not necessarily be the most judicious.
A basic computer is far from being energy efficient. When you only run your computer for a few hours a week, its consumption remains reasonable. But if you have to leave it running 24/7, it becomes problematic because excessive electricity consumption will decrease your return on investment (and harm planet earth 🌏🔥😢). If we take for example a classic 500W pc power supply and a price of 0.23€ per kWh (yes that is the current average price in Europe), this amounts to 1000€ of electricity per year ! It is therefore necessary to find an alternative that uses less energy.
In addition, it is essential to have a stable machine (which is not likely to crash) to avoid being punished by the proof of stake algorithm. This goes through 2 things:
- Have a dedicated machine, which is used exclusively to run the validator. Running other processes could potentially cause conflicts and deprive our Ethereum consensus & execution clients of machine resources. A crash of these could also affect our clients.
- Use Linux, because it is extremely stable and does not need to be restarted often. In addition, it is light and secure. This also reinforces the need to have a dedicated machine because few people are willing to leave Windows or MacOS on their personal machine to switch to this scary beast 🙂
Once that in mind, two choices emerge: have your own hardware or use a VPS.
Self hosting VS using a VPS
Based on the constraints mentioned above, we have 2 choices: buy a computer and plug it in at home OR rent a computer from a host via what is called a VPS (Virtual Private Server). Each solution has its advantages and disadvantages.
Having your own hardware
First solution, buy equipment optimized for our needs and run it at home.
Benefits:
- Cost optimization
By taking care of everything yourself, you avoid paying someone to do it. - Possibility of reselling the equipment
If you ever want to upgrade your equipment or stop your validator activity, you will be able to recover part of your investment by reselling your purchase. - Optimal participation to decentralization
Beyond the financial reward provided by a validator, we must not forget that we are there to support a decentralized network, which therefore needs its participants to be separated as much as possible from a geographic, network, and responsibility point of view. And for that, nothing better than if everyone hosts their node at home. - Physical security
Your validator is at home, no outside person can physically access it to connect to it and retrieve information
Disadvantages:
- Electricity and internet suppliers reliability
As you probably know, Ethereum proof of stake algorithm will punish validators when they go offline. Rest assured this punishment remains low, around 0.3% of the stake for a week offline according to Paul Hauner’s estimates. However, internet contracts for individuals can present a lot of instabilities depending on the case as well as long recovery times in the event of an outage. Professional links are overpriced. Likewise, we are never safe from a power failure. All of this represents a potential shortfall. - Price of electricity
Even with an energy efficient machine, electricity consumption is still a cost to consider. - Equipment maintenance
Computing is great when it works, but when it doesn’t work it’s a hassle, especially when it costs us money! By hosting your validator yourself, it will be necessary to take care of its maintenance yourself in the event of a hardware failure. This can be very disturbing knowing that a failure can happen at any time. - Risk of having unsuitable equipment
As explained above, we do not yet know what the final specs will be once the full roadmap goes into production. By purchasing equipment today, you risk ending up with something underperforming if you go for less and having to buy something else later. Conversely, you can end up with something overperforming if you want to be secure, and have unnecessarily increased the cost of your investment.
Using a VPS
Second solution, renting hardware from a host, in a data center. The advantages and disadvantages of this solution are in fact the opposite of the first.
Benefits:
- Electrical, network, and hardware security
The main advantage of this solution is that you do not have to manage anything regarding the hardware, either for set-up or for maintenance. All you need to do is take out a subscription on a host’s site to have access to a machine. In the event of a power outage, internet or hardware failure, you have nothing to do, the host takes care of everything. Most of them have an uptime (understand a portion of the time when everything is working) of more than 99% ! - Upgradability
Most web hosts offer a live migration option that allows you to switch between plans without having to shut down the services that are running on your machine. Thus, it is very easy to adapt your offer upwards or downwards according to the evolution of your needs and the specifications of your Ethereum clients. - No additional cost on your electricity bill
Energy is included in the offer price.
Disadvantages:
- Premium to pay
A VPS service is generally more expensive in the long run than buying hardware and hosting it yourself. But we will see later that by choosing the right host, a VPS can remain a competitive solution. - Money invested is wasted
We are not the owner of the hardware at any time, and therefore cannot resell it in the event of a activity interruption. - Less decentralization
If everyone goes through a VPS, the validators will all be grouped together in a few data centers around the world, which poses a number of problems with decentralizing the network. In the event of a power failure, an attack on the network, bankruptcy or bad intentions on the part of the host, an entire part of the Ethereum network is in danger. - Physical attack surface
Anyone with access to the datacenter can physically access your validator, connect to it, and retrieve information from it. Although it is highly unlikely that the host will let this sort of thing happen, it still constitutes an attack surface.
How to choose between the two ?
The two solutions both offer advantages and disadvantages, difficult to make a choice ! Let’s take stock of the important points.
The first thing to take into account is the quality of your electricity network and your internet connection. Do you often have cuts from each other ? Is your speed sufficient ? Everything must be stable to be able to self host a validator with complete peace of mind. If you live in the countryside and have a 1 Mega ADSL link, for example, this would not be a good idea. Going through a VPS would therefore be quite appropriate.
The second point to consider is your level of involvement. Are you ready to wake up in the middle of the night or spend half a day on your phone on your vacation halfway around the world to fix a problem on your server ? Do you have the knowledge to anticipate potential hardware problems and stock spare parts accordingly ? Does your home have a place where the machine will be safe from accidents or handling errors by the people you live with ? If so, hosting your own machine is a good idea. If not, it will be necessary to arbitrate.
Hosting your own hardware will save you money in the long run, which will increase your return on your investment. In addition, if the validator is stopped for a short time (from a few hours to a few days), the punishment from the POS algorithm remains negligible. This solution therefore remains viable. On the other hand, a VPS provides peace and serenity. Knowing that you will run this validator for several years, it is important that the load that its maintenance induces is tolerable to you. The choice will therefore be based on this last criterion.
It is also possible to start by installing your validator on a VPS during the first months/years, then to migrate to your own hardware once the protocol is more mature and we have a better vision of how it works and its needs!
You should now have a good idea of the various possibilities that we have. Now let’s go to the concrete part ! What are some interesting hardwares and VPS offers?
Hardware choices
Nano computers, a good idea?
The first instinct of many people was to think of nano computers like the Raspberry Pi or other Odroid. Indeed these machines do not cost much (less than 100€), are rather efficient and consume almost nothing. Taking an average cost of 0.23€ per kWh, such a machine will cost you no more than 6€ of electricity per year!
The tests carried out with current clients are conclusive, the beacon chain works on a Raspberry Pi 4 4 Go. A version for ARM processor (used on nano computers) of Prysm is also available.
However, it is too early to be able to say that these machines will be sufficient in the long term. As explained above, current clients are not necessarily representative of what they will be in the future, once full roadmap goes into production.
There is still a viable option with the Nimbus client for consensus layer which focus on machines with limited power such as smartphones, and Erigon client for execution which is super optimized. These client could be adapted to the resources of a nano computer, but this remains a gamble because it is not finalized and we have no guarantee that it will be maintained in the long term.
If you still want to give this option a try, here’s what you’ll need:
- Raspberry Pi 4 with 8 GB of RAM — 95€
- Power supply — 9€
- Case with cooling system — 13€
- Micro SD card — 12€
- Usb 3 to Sata connector — 9€
- SSD storage — 140€ in 1 TB & 260€ in 2 TB
Total: 278€ with 1 TB of storage / 398€ with 2 TB of storage
Another more powerful option has been explored by the Ethereum on ARM team with the ROCK 5B board. Visit their twitter for more insights !
Better suited: micro computers
Cousins of nano computers, we find micro computers (also called barebones) which are very similar to conventional computers in terms of components. However, they come in a very small size and are much more energy efficient. They therefore make it possible to bring together suitable performance over the long term to run one or more validators, as well as correct consumption.
You will find machines adapted to our case for a budget of 800€ to 1000€. Count between 130€ and 170€ per year for electricity with a price per kWh of 0.23€ depending on the model.
The brand that I recommend to you is Zotac with its C series. It is a little more expensive than the others but has the advantage of offering products that are in the lower bound of yearly consumption price. Backed by their general quality, makes the products more interesting for the long term.
Here are two examples of machines suitable for a validator.
Small configuration respecting the minimum prerequisites:
- Micro pc with an i5 processor — 630€
- 1 TB SSD — 140€
- 4 GB of RAM — 33€
Total: 803€
Big configuration respecting the recommended prerequisites:
- Micro pc with an i7 processor — 800€
- 1 TB SSD — 140€
- 8 GB of RAM — 60€
Total: 1000€
You can also vary the capacity of the SSD and the RAM for the two proposals. A 2 TB SSD or 4 TB SDD will keep you going longer before it’s full (Currently, execution client + consensus client should already pretty much fill out 1 TB). Likewise, you can switch to 8 or 16 GB of RAM for more convenience and keep some headroom for the future.
VPS choice
Let’s move on to VPS. If you already know a little about the subject, you know that it is very expensive among the major players in the market such as Google Cloud, AWS or even Digital Ocean. You would have to pay no less than 40€ per month for a suitable offer.
These hosts offer the advantage of having the most robust infrastructure, but their prices greatly reduce our return on investment, at the current price of ether. Their offers are more suited to huge companies that need impeccable quality of service.
This may be justified in our case in a few years, if ether reaches peak prices and the slightest cut represents a significant loss of income. But for now, it’s not necessary.
Also, their basic offers are not well fitted to our needs since they only offer a few tens of GB storage. That is not enough for an Ethereum node.
Which VPS offer to choose?
There are smaller hosts offering much better rates. The most competitive offer, with good quality of service, that I could find is at Contabo with their VPS S SSD offer at 5€ per month. At this price, it becomes quite viable to delegate material management. It also offers either Europe or US location.
According to my tests, the S offer is sufficient, and even allows the addition of monitoring tools like Prometheus + Grafana. In the future, if clients require more power, it will even be possible to switch to the VPS M SSD offer which offers more than comfortable resources for the price of 10€ per month. A dream !
If you want to run the execution client as well (which is greatly recommended post merge), you will need to choose the VPS XL SSD to have enough storage. This will rise the price to 27€ per month but is still super competitive !
There are other discount VPS hosts. I will not quote more because Contabo remains the best option for me, but you are free to do your research.
Physical security
Only downside: a physical attack is more likely at a small discount host. I am by no means saying that Contabo is not trustworthy, but the internal security measures put in place by a company of this smaller size are likely not to be as drastic as those at AWS et al.
However, this should not scare you. It is in the best interest of all web hosts to do everything to guarantee security and confidentiality with their products to attract and retain their customers. A physical attack is therefore highly unlikely.
Additionally, Ethereum consensus clients have a mechanism to counter intrusions, physical or online. When creating the wallet for your validator, you will be provided with two keys. One is to stop the validator, and the other to withdraw funds. Only the first have to be left on the machine. In the worst case, an attacker who succeeds in breaking into your machine can therefore only stop your validator. Your funds will remain safe.
A final word
We have toured the different options we have to host our validator. It’s up to you to make your choice according to your situation, your preferences and your budget!
Before launching your validator on the mainnet, I urge you to already install a consensus client such as Lighthouse, Lodestar, Teku, Nimbus or Prysm on a testnet to practice.
The operation is not very complicated but can be challenging for computer novices. Intermediates and advanced players may also run into a few subtleties that must be mastered before entering the mainnet on D-Day, and avoid losing the 32 ETH.
To do this, I offer you the excellent Somer Esat articles which explain in detail the configuration of the server, the installation of the execution and consensus clients, the activation of the validator via the launchpad as well as the installation of very useful monitoring tools.
I would also like to mention the existence of Dappnode which offers an open source OS allowing the installation of different clients via a visual interface. This makes it a lot easier for those who hate dealing with the command line 🙂
You are free to choose any client but please, do remember that client diversity is extremely important for security. Thus, avoid running Prysm which still is the majority consensus client. The other clients are just as good !
And if you have any questions or suggestions, you can reach me on Linkedin.
Good luck to you!
Note
The consumption estimates are mentioned here in order to compare the different solutions with each other, and not to anticipate the cost incurred by their use.
This is because the level of operation of a power supply varies with time and conditions. It is therefore not possible to precisely anticipate their consumption in a real situation.
The values mentioned are based on the assumption that the power supplies are operating at maximum capacity at all times. The cost of using them in real life will therefore probably be lower.
Last updated on: 06/2022
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